package day07;

import java.util.Random;

public class VerificationCode_01 {
    public static void main(String[] args) {
        String code = generateVeriCode(4);
        System.out.println("验证码是:"+code);
    }
    public static String generateVeriCode(int len){
        String code = "";
        char[]chs ={'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q',
                    'r','s','t','u','v','w','x','y','z','A','B','C','D','E','F','G','H',
                    'I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y',
                    'Z','0','1','2','3','4','5','6','7','8','9'};
        Random rand = new Random();
        for (int i=1;i<=len;i++){
            int index= rand.nextInt(chs.length);
            code +=chs[index];
        }
        return code;

    }
}
